CVE-2026-53488: Linuxfoundation Containerd Improper Input Validation (CVSS 9.4)

Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.

Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package is affected by bypass of mkdocs configuration sanitizer in techdocs backend. Users with the ability to commit changes to a repository that uses TechDocs can circumvent the MkDocs configuration file sanitizer introduced in response to CVE-2026-25153 and execute arbitrary code on the TechDocs backend host during documentation generation. This issue is fixed in versions 1.14.6 and 1.15.4.

containerd is an open-source container runtime. In Versions prior to 2.3.2, 2.2.5 and 2.1.9, the CRI implementation improperly trusts Container Device Interface (CDI) annotations found within untrusted checkpoint image metadata during container restoration. When restoring a container from a checkpoint, containerd preserves CDI-related annotations from the checkpoint archive rather than relying solely on the pod's create-time specification. This allows a user with pod creation permissions to bypass standard Kubernetes resource allocation and device plugin enforcement, injecting arbitrary CDI edits (such as device nodes and host mounts) into the restored container. Successful exploitation requires that the node has CDI enabled and contains a matching host CDI specification for the requested device; environments where CDI is disabled or lacking sensitive device specifications are not affected. This issue has been fixed in versions 2.3.2, 2.2.5 and 2.1.9.

containerd is an open-source container runtime. In versions prior to 1.7.32, 2.0.9, 2.2.4 and 2.3.1, containers launched with a numeric User directive that cannot be parsed as a 32-bit integer are incorrectly treated as a username, leading to runAsNonRoot evasion. If a crafted image provides an /etc/passwd file mapping this large numeric string to root, the container ultimately runs as root (UID 0). This allows the Kubernetes runAsNonRoot restriction to be bypassed, causing unexpected behavior for environments that require containers to run as a non-root user. This issue has been fixed in versions 1.7.32, 2.0.9, 2.2.4 and 2.3.1.

CloudNativePG is a platform designed to manage PostgreSQL databases within Kubernetes environments. Prior to 1.29.1 and 1.28.3, the CloudNativePG metrics exporter opens its PostgreSQL connection as the postgres superuser via the pod-local Unix socket, then demotes the session with SET ROLE pg_monitor. SET ROLE changes only current_user; session_user remains postgres. Any SQL expression evaluated inside the scrape session can invoke RESET ROLE to recover real superuser privileges, then use COPY ... TO PROGRAM to spawn an OS-level subprocess as the postgres user inside the primary pod. The READ ONLY transaction flag does not block this; it gates writes to database state, not external processes. This vulnerability is fixed in 1.29.1 and 1.28.3.

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 1.0.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, the git resolver's revision parameter is passed directly as a positional argument to git fetch without any validation that it does not begin with a - character. Because git parses flags from mixed positional arguments, an attacker can inject arbitrary git fetch flags such as --upload-pack=<binary>. Combined with the validateRepoURL function explicitly permitting URLs that begin with / (local filesystem paths), a tenant who can submit ResolutionRequest objects can chain these two behaviors to execute an arbitrary binary on the resolver pod. The tekton-pipelines-resolvers ServiceAccount holds cluster-wide get/list/watch on all Secrets, so code execution on the resolver pod enables full cluster-wide secret exfiltration. Versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 fix the issue.